Sprinting, Basketball

First of, Newtons third law of equal and opposite reaction to an action. If you push hard into the ground vertically, then you will produce a resultant vertical force equal to that you produced. So changing the angle of the action - somewhere between vertical and horizontal will give a resultant force at a different angle.

Looking at this as a runner, then foot placement is critical. This will also have an effect on joint angles for the ankle knee and hip. If you have a flexed ankle, knee and hip, when you forcable extend them, you will produce a greater force by allowing the triple extension to push hard into the ground and propel you forward.

The harder than the minimal push into the ground you need to clear the ground for your foot to go forward wastes turnover time, and slows you. Air time is slodown time in the stride. The push up starts when the foot is directly under the body's center. it continues to lift the body until the foot is well behind the center of balance. So the lift does not do all of the pushing at the body at the last moment when it is ahead of the foot. The force to lift the hip is straight up by the leg. Gravity rotates the top of the leg forward. In outer space you can jump straight up from foot to head, but can't take one step forward without gravity.